Material Grade Specification

Inconel 625 Flanges — ASTM B564 UNS N06625

Inconel 625 flange manufacturer, Mumbai. UNS N06625 Ni-Cr-Mo alloy, extreme pitting & thermal resistance from cryogenic to 980°C. Quote in 30 min.

Material Specification & Overview

Inconel 625 (UNS N06625) is a nickel-chromium-molybdenum alloy solid-solution strengthened by Niobium and Molybdenum, exhibiting outstanding resistance to severe oxidation, chloride pitting, and stress corrosion cracking from cryogenic temperatures up to 980°C.

UNS DesignationN06625
Governing StandardASTM B564 / ASME SB-564 UNS N06625

Chemical Composition (wt %)

Governing specification limits per ASTM / ASME standards. Actual values provided on EN 10204 3.1 MTC.

ElementSpecification Limit / Composition
Nickel (Ni)58.0% min
Chromium (Cr)20.0 - 23.0%
Molybdenum (Mo)8.0 - 10.0%
Niobium + Tantalum (Nb+Ta)3.15 - 4.15%

Mechanical Properties

PropertySpecification Limit
Yield Strength414 MPa (60 ksi) min
Tensile Strength827 MPa (120 ksi) min
Elongation30% min
Service Temp RangeCryogenic to 980°C (1,800°F)

Pressure-Temperature Rating Reference

Service TempClass 150Class 300Class 600Class 900
Ambient (-29 to 38°C)290 psi750 psi1500 psi2250 psi

Primary Industry Applications

Subsea sour gas riser piping and flare stacks
Chemical process equipment handling organic and inorganic acids
Marine seawater components exposed to high velocity flow
Nuclear reactor control rod components

Forging, Heat Treatment & Quality Inspection Protocols

Forging & Thermal Processing

Flanges in Inconel 625 Flanges are manufactured via precision closed-die or open-die forging to establish continuous metallurgical grain flow along the flange hub and neck contour. Raw billets are heated in calibrated gas-fired furnaces under strictly controlled soak temperatures to eliminate microstructural defects.

Depending on the alloy grade, components undergo certified thermal conditioning: normalizing for carbon steels (A105N, A350 LF2), rapid water quench solution annealing at 1040°C–1120°C for stainless and duplex grades, or controlled aging for nickel superalloys. This ensures exceptional notch toughness, yield strength, and resistance to stress corrosion cracking.

Dimensional Tolerances & Certification

Final machining is executed on heavy-duty CNC turning centers to guarantee precise raised face, flat face, or ring type joint (RTJ) dimensions compliant with ASME B16.5, ASME B16.47, DIN, or EN 1092-1 standards. Gasket contact surfaces receive spiral or concentric serrations strictly controlled between 125 and 250 µin Ra.

Every production heat is issued with an EN 10204 Type 3.1 inspection certificate containing full heat chemistry, mechanical tensile test data, and Charpy impact values. Independent Third-Party Inspection (TPI) by Lloyd's, BV, DNV-GL, TÜV, and SGS is readily accommodated for global EPC and refinery contracts.

Related Products & Industry Guides

Frequently Asked Procurement Questions

Q: What gives Inconel 625 its high strength without heat treatment?

A: The stiffening effect of Molybdenum and Niobium on the Nickel-Chromium matrix provides high strength without requiring age-hardening heat treatments.

Direct Factory Pricing

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